For the moment I'll concede that I CANNOT find any circumstances where 18 wins from 37 will produce a net loss - and that I was wrong to blame the effect on an excess of odd pairs.

The discredited Martingale system which doubles after each loss only needs 1 win to get back in front.

And I suspect that BJ's system has a similar flaw. Essentially if you have too few wins in 37 spins you will lose. DUH! But the point is those losses will be far bigger than the corresponding wins resulting in an overall loss.

I'll try to think about this more then respond fully.